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C O N F I G U R AT I O N
8.D.9 External
The External Configuration Screen applies to the 0-10VDC (4-20mA) analog input BAS signal, and allows
adjustment of the following parameters:
To navigate to the External Configuration Screen, touch the External Icon on the Configuration Screen.
• Control Mode –
This parameter provides the ability to either disable external control or configure the unit for Boiler Set
Point or Firing Rate control mode.
• Max Set Point –
When the Control Mode is set to Boiler Set Point, this is the maximum value that corresponds to
the Demand Max value.
• Min Set Point –
When the Control Mode is set to Boiler Set Point, this is the minimum value that corresponds to
the Demand Min value.
• Demand Max –
This is the maximum value that corresponds to the control mode selected. With Firing Rate
control mode selected, this is the maximum rate at which the boiler/heater will
run. The unit of this parameter is %, so if the value of this parameter is 10000,
or 100.00%, this equates to 10.0VDC or 20mA.
• Demand Min –
This is the minimum value that corresponds to the control
mode selected. With Firing Rate control mode selected, this is the minimum
rate at which the boiler/heater will run. The
unit of this parameter is %, so if the value
of this parameter is 2000, or 20.00%, this
equates to 2.0VDC or 4.8mA.
• Demand On –
This is the threshold (VDC/
mA) at which the input signal will initiate the
selected control mode behavior. The unit
of this parameter is %, so if the value of this
parameter is 1500, or 15.00%, this equates
to 1.5VDC or 4.6mA.
•
Demand Off –
This is the threshold (VDC/
mA) at which the input signal will deactivate
the selected control mode behavior. The
unit of this parameter is %, so if the value
of this parameter is 1000, or 10.00%, this
equates to 1.0VDC or 4.4mA.
• Input Type –
This parameter allows the
user to select between voltage (0-10VDC)
or current (4-20mA) input. Jumpers will
need to be configured accordingly.
• Heat Demand -
Allows an installer to use
the VDC/mA signal as the heat demand
signal as well as the external firing rate/
set point signal OR to use an external heat
demand (CH1/DHW1, CH2/DHW2, DHW/
DHW3) as the heat demand while the VDC/
mA only provides the external firing rate/set
point signal.
NOTE: If an external heat demand
option is chosen, the ‘Demand On’
and ‘Demand Off’ buttons will be
grayed out.
LAARS Heating Systems
